Structured depilatory compositions

ABSTRACT

Provided are compositions comprising a depilatory active; and a surfactant, wherein the composition has a Yield Stress of from about 1 Pascal (Pa) to about 1500 Pa, and methods of use thereof.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of priority to U.S. ProvisionalApplication Ser. No. 60/947,000 filed Jun. 29, 2007.

FIELD OF INVENTION

The present invention relates to structured compositions comprising adepilatory, and uses of such compositions in personal care products.

DESCRIPTION OF THE RELATED ART

A variety of so-called “structured” compositions for use in personalcare, home care, and other consumer products are known in the art. Suchstructured compositions are often typified by the presence of alamellar, surfactant-rich phase, and tend to exhibit desirablerheological and aesthetic properties, as well as, significant power tosuspend functional ingredients that are not soluble in water.

Applicants have recognized that, it would be desirable to combine thefavorable rheology and aesethetics of a structured system with adepilatory active system. Applicants have further recognized that itwould also be desirable to create a depilatory composition that is notonly aesthetically pleasing and/or phase-stable, but also exhibits oneor more additional properties such as rinsability and/or mildness.However, applicants have additionally recognized that the incorporationof depilatories into structured systems tends to be problematic. Inparticular, applicants believe that the (1) aggressive nature ofdepilatory actives as well as (2) the high levels of electrolyte thatare often required to augment the efficacy of the depilatory, make itdifficult to form a stable structured depilatory composition.

In light of the above, applicants have recognized the need to developstructured compositions comprising a depilatory active, and methods ofmaking such compositions.

SUMMARY OF THE INVENTION

The present invention meets the aforementioned need and overcomes thedisadvantages of the prior art. In particular, applicants havediscovered that one or more depilatory actives can be combined with oneor more surfactants to produce structured compositions that are phasestable.

According to one aspect, the present invention provides a compositioncomprising a depilatory active and a surfactant, the composition havinga Yield Stress of from about 1 Pascal (Pa) to about 1500 Pa.

According to one aspect, the present invention provides methods ofmaking a structured composition comprising combining a depilatory activeand a surfactant in amounts sufficient to achieve a composition having aYield Stress of from about 1 Pascal (Pa) to about 1500 Pa.

According to another aspect, the present invention provides methods ofremoving hair from the human body comprising applying a structuredcomposition of the present invention to the human body for a period oftime sufficient to enhance the removal of hair therefrom.

DESCRIPTION OF PREFERRED EMBODIMENTS

All percentages listed in this specification are percentages by weight,unless otherwise specifically mentioned.

As used herein the term “structured composition,” means a compositionhaving a Yield Stress from about 1 Pascal (Pa) to about 1500 Pa asmeasured via the “Yield Stress Test” described in the Test Methodsbelow. Examples of certain preferred structured compositions includethose having a Yield Stress of from about 10 Pa to about 1100 Pa, asmeasured by the Yield Stress Method described hereafter.

As noted above, applicants have discovered unexpectedly that structuredcompositions may be obtained by combining at least one depilatory activewith at least one surfactant. Applicants have further discovered thatcompositions of the instant invention, according to certain embodimentshave the desirable attribute that may be referred to as “heaping,” i.e.the ability to recover shape rapidly and form peaks when subject toshearing, as determined by the “Degree of Heaping Test” described in theTest Methods below. Accordingly, in certain embodiments, the inventivecompositions have a Hauesorff-Besicovitch Dimension (hereinafter, “H-BDimension”) that is less than about 1.7, preferably less than about 1.6,more preferably less than about 1.5, and even more preferably less thanabout 1.4, as measured by the Degree of Heaping Test Method describedhereafter.

Any of a variety of suitable depilatory actives may be used in thecompositions of the present invention. By depilatory active, it is meanta chemical species that is capable of chemically degrading hair and istherefore meant to exclude those species, e.g., waxes that function toremove hair solely by physically bonding thereto so that the hair may bemechanically torn from the body. Examples of suitable depilatory activesinclude any of those compounds suitable for chemically degrading keratinor hair (such as by disrupting disulfide bonds of the hair). Suitableexamples of depilatory actives include thio-containing compounds thatmay be either ionized or unionized, water soluble or water-dispersible.Examples of suitable depilatory actives include thioglycolates such aspotassium thioglycolate, dithioerythritol, thioglycerol, thioglycol,thioxanthine, thiosalicylic acid, N-acetyl-L-cysteine′ lipoic acid,sodium dihydrolipoate 6,8 dithicocatanoate, sodium6,8-diothioocatanoate, a hydrogen sulphide salt, thioglycolic acid,2-mercaptopropionic acid, 3-mercaptopropionic acid, thiomalic acid,ammonium thioglycolate′ glyceryl monothioglycolate, monoethanolaminethioglycolate′ monoethanolamine thioglycolic acid,diammoniumdithiodiglycolate, ammonium thiolactate, monoethanolaminethiolactate, thioglycolamide, homocysteine, cysteine, glutathione,dithiothreitol, dihydrolipoic acid, 1′3-dithiopropanol, thioglycolamide,glycerylmonothioglycolate, thioglycolhydrazine, keratinase, guanidinethioglycolate, calcium thioglycolate and/or cysteamine, and combinationsthereof. Particularly suitable depilatory actives are thioglycolates.

Any of a variety of suitable surfactants may be used in the compositionsof the present invention, preferably such that the final composition haseither a Yield Stress of from about 1 Pascal (Pa) to about 1500 Paand/or and H-B dimension of less than about 1.7. In one embodiment, thecomposition includes an anionic surfactant. According to certainembodiments, suitable anionic surfactants may be branched or unbranchedand may include alkyl olefin sulfonates, alkyl sulfates, alkyl ethersulfates, alkyl monoglyceryl ether sulfates, alkyl sulfonates, alkylarylsulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylsulfosuccinamates, alkyl amidosulfosuccinates, alkyl carboxylates, alkylamidoethercarboxylates, alkyl succinates, fatty acyl sarcosinates, fattyacyl amino acids, fatty acyl taurates, fatty alkyl sulfoacetates, alkylphosphates, and mixtures of two or more thereof. Examples of certainanionic surfactants include:

alkyl olefin sulfonates of the formulaR′—CH₂SO₃X′;

alkyl ether sulfates of the formulaR′(OCH₂CH₂)_(v)OSO₃X′;

alkyl sulfates of the formulaR′—CH₂OSO₃X′;

alkyl monoglyceryl ether sulfates of the formula

alkyl monoglyceride sulfates of the formula

alkyl monoglyceride sulfonates of the formula

alkyl sulfonates of the formulaR′—SO₃X′;

alkylaryl sulfonates of the formula

alkyl sulfosuccinates of the formula:

alkyl ether sulfosuccinates of the formula:

alkyl sulfosuccinamates of the formula:

alkyl amidosulfosuccinates of the formula

alkyl carboxylates of the formula:R′—(OCH₂CH₂)_(w)—OCH₂CO₂X′;

alkyl amidoethercarboxylates of the formula:

alkyl succinates of the formula:

fatty acyl sarcosinates of the formula:

fatty acyl amino acids of the formula:

fatty acyl taurates of the formula:

fatty alkyl sulfoacetates of the formula:

alkyl phosphates of the formula:

wherein

-   -   R′ is an alkyl group having from about 7 to about 22, and        preferably from about 7 to about 16 carbon atoms,    -   R′₁ is an alkyl group having from about 1 to about 18, and        preferably from about 8 to about 14 carbon atoms,    -   R′₂ is a substituent of a natural or synthetic 1-amino acid,    -   X′ is selected from the group consisting of alkali metal ions,        alkaline earth metal ions, ammonium ions, and ammonium ions        substituted with from about 1 to about 3 substituents, each of        the substituents may be the same or different and are selected        from the group consisting of alkyl groups having from 1 to 4        carbon atoms and hydroxyalkyl groups having from about 2 to        about 4 carbon atoms and    -   v is an integer from 1 to 6;    -   w is an integer from 0 to 20;        and mixtures thereof.

Preferred anionic surfactants include alkyl olefin sulfonates and alkylether sulfates. One particularly suitable anionic surfactant is a sodiumalkyl olefin sulfonate, available as BIOTERGE SD40 MFLD from StepanCompany of Northfield, Ill.

In certain preferred embodiments, the anionic surfactant for use in thepresent invention comprises a branched anionic surfactant. By “branchedanionic surfactant,” it is meant an anionic surfactant comprising morethan 10% branched surfactant molecules. Suitable branched anionicsurfactants include tridecanol based sulfates such as sodium tridecethsulfate, which generally comprises a high level of branching, with over80% of surfactant molecules comprising at least 2 branches. Anothersuitable branched anionic surfactant is a C₁₂₋₁₃ alkyl sulfate derivedfrom SAFOL 23 alcohol (Sasol, Inc, Houston, Tex., USA) which has about15-30% branched surfactant molecules.

Branched anionic surfactants include but are not limited to thefollowing branched anionic alkyl sulfate or alkyl ether sulfatesurfactants: sodium tridecyl sulfate, sodium C₁₂₋₁₃ alkyl sulfate,sodium C₁₂₋₁₅ alkyl sulfate, sodium C₁₂₋₁₅ alkyl sulfate, sodium C₁₂₋₁₈alkyl sulfate, sodium C₁₀₋₁₆ alkyl sulfate, sodium trideceth sulfate,sodium C₁₂₋₁₃ pareth sulfate, sodium C₁₂₋₁₃ pareth-n sulfate, and sodiumC₁₂₋₁₄ pareth-n sulfate. One particularly suitable branched anionicsurfactant (about 50% branched) is a sodium trideceth sulfate, availableas CEDEPAL TD 430 MFLD from Stepan Company of Northfield, Ill.

Other salts of all the aforementioned branched anionic surfactants areuseful, such as TEA, DEA, ammonia, potassium salts. Useful alkoxylatesinclude the ethylene oxide, propylene oxide and EO/PO mixed alkoxylates.Phosphates, carboxylates and sulfonates prepared from branched alcoholsare also useful anionic branched surfactants. Branched anonicsurfactants can be derived from synthetic alcohols such as the primaryalcohols from the liquid hydrocarbons produced by Fischer-Tropschcondensed syngas, for example SAFOL 23 Alcohol available from SasolNorth America, Houston, Tex.; from synthetically made alcohols such asthose described in U.S. Pat. No. 6,335,312 issued to Coffindaffer, et alon Jan. 1, 2002. Preferred alcohols are SAFOL™ 23. Preferred alkoxylatedalcohols are SAFOL 23-3. Sulfates can be prepared by conventionalprocesses to high purity from a sulfur based SO₃ air stream process,chlorosulfonic acid process, sulfuric acid process, or Oleum process.Preparation via SO₃ air stream in a falling film reactor is a preferredsulfation process.

Suitable branched anionic surfactants include but are not limited to thebranched anionic sulfates derived from SAFOL 23-n as previouslydescribed, where n is an integer between 1 and about 20. Fractionalalkloxylation is also useful, for example by stoichiometrically addingonly about 0.3 moles EO, or 1.5 moles EO, or 2.2 moles EO, based on themoles of alcohol present, since the molecular combinations that resultare in fact always distributions of alkoxylates so that representationof n as an integer is merely an average representation. Preferredmonomethyl branched anionic surfactants include a C₁₂₋₁₃ alkyl sulfatederived from the sulfation of SAFOL 23, which has about 28% branchedanionic surfactant molecules.

When the branched anionic surfactant is a branched anionic primarysulfate, it may contain some of the following branched anionicsurfactant molecules: 4-methyl undecyl sulfate, 5-methyl undecylsulfate, 7-methyl undecyl sulfate, 8-methyl undecyl sulfate, 7-methyldodecyl sulfate, 8-methyl-dodecyl sulfate, 9-methyl dodecyl sulfate,4,5-dimethyl decyl sulfate, 6,9-dimethyl decyl sulfate, 6,9-dimethylundecyl sulfate, 5-methyl-8-ethyl undecyl sulfate, 9-methyl undecylsulfate, 5,6,8-trimethyl decyl sulfate, 2-methyl dodecyl sulfate, and2-methyl undecyl sulfate. When the anionic surfactant is a primaryalkoxylated sulfate, these same molecules may be present as the n=0unreacted alcohol sulfates, in addition to the typical alkoxylatedadducts that result from alkoxylation.

Any amounts of anionic surfactant or combinations thereof suitable to,in conjunction with other ingredients in the composition to produce astructured composition is suitable. According to certain embodiments,anionic surfactant is used in a concentration from greater than about0.1% to about 30% by weight of active anionic surfactant in thecomposition. However to provide sufficient structuring, preferably theanionic surfactant is used in a higher concentration, preferably fromabout 2% to about 30%, more preferably from about 7% to about 25%, evenmore preferably from about 10% to about 22% of active anionic surfactantin the composition.

Any of a variety of suitable betaines may be used in the compositions ofthe present invention. Examples of suitable betaines include alkylbetaines; amidoalkyl betaines; amidoalkyl sultaines; amphophosphates;phosphorylated imidazolines such as phosphobetaines andpyrophosphobetaines, as well as other betaines represented by thefollowing formula:B—N⁺R₁R₂(CH₂)_(p)X⁻wherein B is an alkyl or alkenyl group, preferably a group having fromabout 7 to about 22 carbon atoms; and X⁻ is a anionically charged moietyor a neutral (protonated) derivative thereof. As will be recognized bythose of skill in the art, the charge on X⁻ may be dependent on the pHof the composition.

Examples of suitable alkyl betaines include those compounds of theformula:D-N⁺R₉R₁₀(CH₂)_(p)CO₂ ⁻

-   -   wherein        -   D is an alkyl or alkenyl group having from about 8 to about            22, e.g., from about 8 to about 16 carbon atoms;        -   R₉ and R₁₀ are each independently an alkyl or hydroxyalkyl            group having from about 1 to about 4 carbon atoms; and        -   p is 1 or 2.            A preferred betaine for use in the present invention is            lauryl betaine, available commercially from Huntsman            International LLC of The Woodlands, Tex., as “Empigen BB/J.”

Examples of suitable amidoalkyl betaines include those compounds of theformula:F—CO—NH(CH₂)_(q)—N⁺R₁₁R₁₂(CH₂)_(m)CO₂ ⁻

-   -   wherein        -   F is an alkyl or alkenyl group having from about 7 to about            21, e.g. from about 7 to about 15 carbon atoms;        -   R₁₁ and R₁₂ are each independently an alkyl or Hydroxyalkyl            group having from about 1 to about 4 carbon atoms;        -   q is an integer from about 2 to about 6; and m is 1 or 2.            One amidoalkyl betaine is cocamidopropyl betaine, available            commercially from Degussa Goldschmidt Chemical Corporation            of Hopewell, Va. under the tradename, “Tegobetaine L7.”

Examples of suitable amidoalkyl sultaines include those compounds of theformula

-   -   wherein        -   E is an alkyl or alkenyl group having from about 7 to about            21, e.g. from about 7 to about 15 carbon atoms;        -   R₁₄ and R₁₅ are each independently an alkyl, or hydroxyalkyl            group having from about 1 to about 4 carbon atoms;        -   r is an integer from about 2 to about 6; and        -   R₁₃ is an alkylene or hydroxyalkylene group having from            about 2 to about 3 carbon atoms;

In one embodiment, the amidoalkyl sultaine is cocamidopropylhydroxysultaine, available commercially from Rhodia Inc. of Cranbury,N.J. under the tradename, “Mirataine CBS.”

Examples of suitable amphophosphates compounds include those of theformula:

-   -   wherein        -   G is an alkyl or alkenyl group having about 7 to about 21,            e.g. from about 7 to about 15 carbon atoms;            -   s is an integer from about 2 to about 6;            -   R₁₆ is hydrogen or a carboxyalkyl group containing from                about 2 to about 3 carbon atoms;            -   R₁₇ is a hydroxyalkyl group containing from about 2 to                about 3 carbon atoms or a group of the formula:                R₁₉—O—(CH₂)_(t)—CO₂ ⁻    -   wherein        -   R₁₉ is an alkylene or hydroxyalkylene group having from            about 2 to about 3 carbon atoms and        -   t is 1 or 2; and    -   R₁₈ is an alkylene or hydroxyalkylene group having from about 2        to about 3 carbon atoms.

In one embodiment, the amphophosphate compounds are sodium lauroamphoPG-acetate phosphate, available commercially from Uniqema of Chicago,Ill. under the tradename, “Monateric 1023,” and those disclosed in U.S.Pat. No. 4,380,637, which is incorporated herein by reference.

Examples of suitable phosphobetaines include those compounds of theformula:

wherein E, r, R₁, R₂ and R₃, are as defined above. In one embodiment,the phosphobetaine compounds are those disclosed in U.S. Pat. Nos.4,215,064, 4,617,414, and 4,233,192, which are all incorporated hereinby reference.

Examples of suitable pyrophosphobetaines include those compounds of theformula:

wherein E, r, R₁, R₂ and R₃, are as defined above. In one embodiment,the pyrophosphobetaine compounds are those disclosed in U.S. Pat. Nos.4,382,036, 4,372,869, and 4,617,414, which are all incorporated hereinby reference.

Any amount of betaine or combination of betaines suitable, inconjunction with other ingredients in the composition, to produce astructured composition may be used in accord with the invention.According to certain embodiments, betaine is used in a concentrationfrom greater than about 0.1% to about 50% by weight of active betaine inthe composition. Preferably, betaine is in present in a concentrationfrom about 1% to about 40%, more preferably from about 5% to about 40%,even more preferably from about 15% to about 35% of active betaine inthe composition.

Compositions of the present invention may further include a structuringaid such as a C7-C22, linear or branched fatty acids or fatty alcoholsthat enhances the ability of the surfactant(s) to exist in astructured/lamellar phase. The structuring aid may be a conventionalstructuring aid such as oleic acid, oleyl alcohol, lauryl alcohol andthe like. In one embodiment, the structuring aid is a branched fattyalcohol. Any of a variety of branched fatty alcohols may be used in thepresent compositions. By “branched fatty alcohol”, it is meant, any ofvarious alcohols derived from plant or animal oils and fats having atleast one pendant hydrocarbon-comprising chain. The branched fattyalcohol may comprise any number of carbon atoms, preferably from about 7to about 22 carbon atoms, more preferably about 9 to about 15 carbonatoms, and even more preferably about 11 to about 15 carbon atoms.Suitable branched fatty alcohols may comprise one or more alcohol groupsper molecule. In certain preferred embodiments, the fatty alcoholcomprises one alcohol group per molecule.

Suitable branched fatty alcohols may comprise one or more branches inthe carbon backbone of the molecule. In certain preferred embodiments,the branched fatty alcohol is monobranched. By “monobranched”, it ismeant the fatty alcohol has an alkyl chain with one (CH) functionalgroup resulting in one branch in the alkyl chain, i.e. the fatty alcoholhas one and only one carbon that has one hydrogen atom and three carbonatoms bonded thereto.

In certain preferred embodiments, the branched fatty alcohol is aprimary alcohol. By “primary alcohol,” it is meant no —COH group isbonded to more than one carbon atom.

In one particularly preferred embodiment, the branched fatty alcohol isboth monobranched and a primary alcohol. In a more particularlypreferred embodiment, the branched fatty alcohol is both monobranchedand a primary alcohol and has only one alcohol group per molecule.

In certain preferred embodiments, the branched fatty alcohol consistssolely of hydrogen, carbon, and oxygen atoms. The carbon-carbon bondswithin the branched fatty alcohol may be saturated or unsaturated.

In one particularly preferred embodiment, the branched fatty alcohol isa monobranched primary fatty alcohol that can be represented by thefollowing structure:

wherein each of the three following equations are satisfied: m+n=8 or 9;and m is an integer that ranges from 0 to 9 (inclusive); and n is aninteger that ranges from 0 to 9 (inclusive).

Commercially available materials that are particularly suitable for useas the branched fatty alcohol include the following materials alone orin combination: Isalchem 123 or Lialchem 123 produced by Sasol ChemicalCo of Bad Homburg, Germany. In a particularly preferred embodiment, thebranched fatty alcohol is Isalchem 123.

In another embodiment, the branched fatty alcohol includes an alkoxylatemoiety, such as ethoxy and/or propoxy groups. Any number of alkoxygroups are acceptable as long as the fatty alcohol is still capable ofproviding a structured composition. In one embodiment, the fatty alcoholhas up to an including 10 alkoxy groups, more preferably from 0 to 3alkoxy groups, most preferably from 1 to 3 alkoxy groups.

The concentration of the branched fatty alcohol in the composition ofthe invention is preferably from about 0.1% to about 10% by weight ofactive branched fatty alcohol in the composition, more preferably from0.5% to about 5% by weight, even more preferably from about 0.75% toabout 4%.

In one embodiment of the invention, the branched fatty alcohol andbetaine are present in a fatty alcohol to betaine (weight to weight, onan actives basis) ratio that is from about 0.15:1 to about 0.35:1.

Any of a variety of suitable anionic surfactants may be used in thepresent invention. According to certain embodiments, suitable anionicsurfactants may be branched or unbranched and may include alkylsulfates, alkyl ether sulfates, alkyl monoglyceryl ether sulfates, alkylsulfonates, alkylaryl sulfonates, alkyl sulfosuccinates, alkyl ethersulfosuccinates, alkyl sulfosuccinamates, alkyl amidosulfosuccinates,alkyl carboxylates, alkyl amidoethercarboxylates, alkyl succinates,fatty acyl sarcosinates, fatty acyl amino acids, fatty acyl taurates,fatty alkyl sulfoacetates, alkyl phosphates, and mixtures of two or morethereof. Examples of certain anionic surfactants include:

alkyl sulfates of the formulaR′—CH₂OSO₃X′;

alkyl ether sulfates of the formulaR′(OCH₂CH₂)_(v)OSO₃X′;

alkyl monoglyceryl ether sulfates of the formula

alkyl monoglyceride sulfates of the formula

alkyl monoglyceride sulfonates of the formula

alkyl sulfonates of the formulaR′—SO₃X′;

alkylaryl sulfonates of the formula

alkyl sulfosuccinates of the formula:

alkyl ether sulfosuccinates of the formula:

alkyl sulfosuccinamates of the formula:

alkyl amidosulfosuccinates of the formula

alkyl carboxylates of the formula:R′—(OCH₂CH₂)_(w)—OCH₂CO₂X′;

alkyl amidoethercarboxylates of the formula:

alkyl succinates of the formula:

fatty acyl sarcosinates of the formula:

fatty acyl amino acids of the formula:

fatty acyl taurates of the formula:

fatty alkyl sulfoacetates of the formula:

alkyl phosphates of the formula:

wherein

-   -   R′ is an alkyl group having from about 7 to about 22, and        preferably from about 7 to about 16 carbon atoms,    -   R′₁ is an alkyl group having from about 1 to about 18, and        preferably from about 8 to about 14 carbon atoms,    -   R′₂ is a substituent of a natural or synthetic 1-amino acid,    -   X′ is selected from the group consisting of alkali metal ions,        alkaline earth metal ions, ammonium ions, and ammonium ions        substituted with from about 1 to about 3 substituents, each of        the substituents may be the same or different and are selected        from the group consisting of alkyl groups having from 1 to 4        carbon atoms and hydroxyalkyl groups having from about 2 to        about 4 carbon atoms and    -   v is an integer from 1 to 6;    -   w is an integer from 0 to 20;        and mixtures thereof.

In certain preferred embodiments, the anionic surfactant for use in thepresent invention comprises a branched anionic surfactant. By “branchedanionic surfactant,” it is meant an anionic surfactant comprising morethan 10% branched surfactant molecules. Suitable branched anionicsurfactants include tridecanol based sulfates such as sodium tridecethsulfate, which generally comprises a high level of branching, with over80% of surfactant molecules comprising at least 2 branches. Anothersuitable branched anionic surfactant is a C₁₂₋₁₃ alkyl sulfate derivedfrom SAFOL 23 alcohol (Sasol, Inc, Houston, Tex., USA) which has about15-30% branched surfactant molecules.

Branched anionic surfactants include but are not limited to thefollowing branched anionic alkyl sulfate or alkyl ether sulfatesurfactants: sodium tridecyl sulfate, sodium C₁₂₋₁₃ alkyl sulfate,sodium C₁₂₋₁₅ alkyl sulfate, sodium C₁₂₋₁₅ alkyl sulfate, sodium C₁₂₋₁₈alkyl sulfate, sodium C₁₀₋₁₆ alkyl sulfate, sodium trideceth sulfate,sodium C₁₂₋₁₃ pareth sulfate, sodium C₁₂₋₁₃ pareth-n sulfate, and sodiumC₁₂₋₁₄ pareth-n sulfate. One particularly suitable branched anionicsurfactant (about 50% branched) is a sodium trideceth sulfate, availableas CEDEPAL TD 430 MFLD from Stepan Company of Northfield, Ill.

Other salts of all the aforementioned branched anionic surfactants areuseful, such as TEA, DEA, ammonia, potassium salts. Useful alkoxylatesinclude the ethylene oxide, propylene oxide and EO/PO mixed alkoxylates.Phosphates, carboxylates and sulfonates prepared from branched alcoholsare also useful anionic branched surfactants. Branched anonicsurfactants can be derived from synthetic alcohols such as the primaryalcohols from the liquid hydrocarbons produced by Fischer-Tropschcondensed syngas, for example SAFOL 23 Alcohol available from SasolNorth America, Houston, Tex.; from synthetically made alcohols such asthose described in U.S. Pat. No. 6,335,312 issued to Coffindaffer, et alon Jan. 1, 2002. Preferred alcohols are SAFOL™ 23. Preferred alkoxylatedalcohols are SAFOL 23-3. Sulfates can be prepared by conventionalprocesses to high purity from a sulfur based SO₃ air stream process,chlorosulfonic acid process, sulfuric acid process, or Oleum process.Preparation via SO₃ air stream in a falling film reactor is a preferredsulfation process.

Suitable branched anionic surfactants include but are not limited to thebranched anionic sulfates derived from SAFOL 23-n as previouslydescribed, where n is an integer between 1 and about 20. Fractionalalkloxylation is also useful, for example by stoichiometrically addingonly about 0.3 moles EO, or 1.5 moles EO, or 2.2 moles EO, based on themoles of alcohol present, since the molecular combinations that resultare in fact always distributions of alkoxylates so that representationof n as an integer is merely an average representation. Preferredmonomethyl branched anionic surfactants include a C₁₂₋₁₃ alkyl sulfatederived from the sulfation of SAFOL 23, which has about 28% branchedanionic surfactant molecules.

When the branched anionic surfactant is a branched anionic primarysulfate, it may contain some of the following branched anionicsurfactant molecules: 4-methyl undecyl sulfate, 5-methyl undecylsulfate, 7-methyl undecyl sulfate, 8-methyl undecyl sulfate, 7-methyldodecyl sulfate, 8-methyl-dodecyl sulfate, 9-methyl dodecyl sulfate,4,5-dimethyl decyl sulfate, 6,9-dimethyl decyl sulfate, 6,9-dimethylundecyl sulfate, 5-methyl-8-ethyl undecyl sulfate, 9-methyl undecylsulfate, 5,6,8-trimethyl decyl sulfate, 2-methyl dodecyl sulfate, and2-methyl undecyl sulfate. When the anionic surfactant is a primaryalkoxylated sulfate, these same molecules may be present as the n=0unreacted alcohol sulfates, in addition to the typical alkoxylatedadducts that result from alkoxylation.

Any amounts of branched anionic surfactant or combinations thereofsuitable to, in conjunction with other ingredients in the composition toproduce a structured composition is suitable. According to certainembodiments, branched anionic surfactant is used in a concentration fromgreater than about 0.1% to about 20% by weight of active branchedanionic surfactant in the composition. Preferably, branched anionicsurfactant is in present in a concentration from about 0.3% to about15%, more preferably from about 2% to about 15%, even more preferablyfrom about 4.5% to about 12% of active branched anionic surfactant inthe composition.

Additional surfactants, such as amphoteric, cationic, non-ionic, orcombinations thereof may be used in compositions of the presentinvention. For example, any of a variety of amphoteric surfactants aresuitable for use in the present invention. The amphoteric surfactantsare disclosed herein without a counter ion. One skilled in the art wouldreadily recognize that under the pH conditions of the compositions ofthe present invention, the amphoteric surfactants are eitherelectrically neutral by virtue of having balancing positive and negativecharges, or they have counter ions such as alkali metal, alkaline earth,or ammonium counter ions.

Examples of amphoteric surfactants include, but are not limited to“betaines” as defined above as well as amphocarboxylates such asalkylamphoacetates (mono or di); phosphorylated imidazolines such asphosphobetaines and pyrophosphobetaines; carboxyalkyl alkyl polyamines;alkylimino-dipropionates; alkylamphoglycinates (mono or di);alkylamphoproprionates (mono or di)); N-alkyl β-aminoproprionic acids;alkylpolyamino carboxylates; and mixtures thereof.

Examples of suitable amphocarboxylate compounds include those of theformula:A-CONH(CH₂)_(x)N⁺R₅R₆R₇

-   -   wherein    -   A is an alkyl or alkenyl group having from about 7 to about 21,        e.g. from about 10 to about 16 carbon atoms;    -   x is an integer of from about 2 to about 6;    -   R₅ is hydrogen or a carboxyalkyl group containing from about 2        to about 3 carbon atoms;    -   R₆ is a hydroxyalkyl group containing from about 2 to about 3        carbon atoms or is a group of the formula:        R₈—O—(CH₂)_(n)CO₂ ⁻    -   wherein    -   R₈ is an alkylene group having from about 2 to about 3 carbon        atoms and n is 1 or 2; and    -   R₇ is a carboxyalkyl group containing from about 2 to about 3        carbon atoms;

Examples of suitable amphophosphate compounds include those of theformula:

-   -   wherein        -   G is an alkyl or alkenyl group having about 7 to about 21,            e.g. from about 7 to about 15 carbon atoms;            -   s is an integer from about 2 to about 6;            -   R₁₆ is hydrogen or a carboxyalkyl group containing from                about 2 to about 3 carbon atoms;            -   R₁₇ is a hydroxyalkyl group containing from about 2 to                about 3 carbon atoms or a group of the formula:                R₁₉—O—(CH₂)_(t)—CO₂ ⁻    -   wherein        -   R₁₉ is an alkylene or hydroxyalkylene group having from            about 2 to about 3 carbon atoms and        -   t is 1 or 2; and    -   R₁₈ is an alkylene or hydroxyalkylene group having from about 2        to about 3 carbon atoms.

In one embodiment, the amphophosphate compounds are sodium lauroamphoPG-acetate phosphate, available commercially from Uniqema of Chicago,Ill. under the tradename, “Monateric 1023,” and those disclosed in U.S.Pat. No. 4,380,637, which is incorporated herein by reference.

Examples of suitable carboxyalkyl alkylpolyamines include those of theformula:

-   -   wherein        -   I is an alkyl or alkenyl group containing from about 8 to            about 22, e.g. from about 8 to about 16 carbon atoms;        -   R₂₂ is a carboxyalkyl group having from about 2 to about 3            carbon atoms;        -   R₂₁ is an alkylene group having from about 2 to about 3            carbon atoms and        -   u is an integer from about 1 to about 4.

In one embodiment, in order to provide a high degree ofcost-effectiveness, the weight fraction of betaine relative to allamphoteric surfactants in the composition is at least about 25%,preferably at least about 50%, and most preferably at least about 75%.

Various nonionic surfactants may also be suitable. Examples of suitablenonionic surfactants include, but are not limited to, fatty alcoholethoxylates, fatty alcohol acid or amide ethoxylates, monoglycerideethoxylates, sorbitan ester ethoxylates alkyl polyglycosides, mixturesthereof, and the like. Certain preferred nonionic surfactants includepolyoxyethylene derivatives of polyol esters, wherein thepolyoxyethylene derivative of polyol ester (1) is derived from (a) afatty acid containing from about 8 to about 22, and preferably fromabout 10 to about 14 carbon atoms, and (b) a polyol selected fromsorbitol, sorbitan, glucose, α-methyl glucoside, polyglucose having anaverage of about 1 to about 3 glucose residues per molecule, glycerine,pentaerythritol and mixtures thereof, (2) contains an average of fromabout 10 to about 120, and preferably about 20 to about 80 oxyethyleneunits; and (3) has an average of about 1 to about 3 fatty acid residuesper mole of polyoxyethylene derivative of polyol ester. Examples of suchpreferred polyoxyethylene derivatives of polyol esters include, but arenot limited to PEG-80 sorbitan laurate and Polysorbate 20. PEG-80sorbitan laurate, which is a sorbitan monoester of lauric acidethoxylated with an average of about 80 moles of ethylene oxide, isavailable commercially from Uniqema of Chicago, Ill. under thetradename, “Atlas G-4280.” Polysorbate 20, which is the lauratemonoester of a mixture of sorbitol and sorbitol anhydrides condensedwith approximately 20 moles of ethylene oxide, is available commerciallyfrom ICI Surfactants of Wilmington, Del. under the tradename “Tween 20.”

Another class of suitable nonionic surfactants includes long chain alkylglucosides or polyglucosides, which are the condensation products of (a)a long chain alcohol containing from about 6 to about 22, and preferablyfrom about 8 to about 14 carbon atoms, with (b) glucose or aglucose-containing polymer. Preferred alkyl gluocosides comprise fromabout 1 to about 6 glucose residues per molecule of alkyl glucoside. Apreferred glucoside is decyl glucoside, which is the condensationproduct of decyl alcohol with a glucose polymer and is availablecommercially from Cognis Corporation of Ambler, Pa. under the tradename,“Plantaren 2000.”

Any amounts of nonionic surfactant suitable to produce a structuredcomposition may be combined according to the present methods. Forexample, the amount of nonionic surfactants used in the presentinvention may be from about 2% to about 30%, more preferably from about3% to about 25%, even more preferably from about 8% to about 20% oftotal active nonionic surfactant in the composition, and even morepreferably from about 9% to about 15%.

Various cationic surfactants may also be suitable for use in the presentcompositions. Examples of suitable cationic surfactants include, but arenot limited to alkyl quaternaries (mono, di, or tri), benzylquaternaries, ester quaternaries, ethoxylated quaternaries, alkylamines, and mixtures thereof, wherein the alkyl group has from about 6carbon atoms to about 30 carbon atoms, with about 8 to about 22 carbonatoms being preferred.

It is desirable that the composition is free or substantially free ofsurfactants that tend to create problems with the stability of thecomposition (e.g., phase stability and/or stability of viscosity, pH andthe like). For example, in certain embodiments it is preferred that thecomposition is free or substantially free of surfactants having one ormore amide functional groups. As used herein, the term “substantiallyfree” means the composition comprises less than about 5% by weight ofsurfactants having one or more amide functional groups. In certain morepreferred embodiments the composition comprises less than about 2%, morepreferably less than about 1%, more preferably less than about 0.5% ofsurfactants having one or more amide functional groups. Examples ofsurfactants having one or more amide functional groups include but arenot limited to betaines, amine oxides, amphoacetates, and the like.

Compositions of the present invention generally include pH modifiers,e.g., sufficient hydroxyl ions to provide a pH suitable for depilation.The hydroxyl ions may be provided by alkali metal hydroxides, e.g.,hydroxides of lithium, sodium, potassium, rubidium, and cesium; withsodium and potassium preferred. Sufficient alkali metal hydroxide may beused in the composition so as to provide a total alkali metal ionconcentration of at least 1.5% by weight, preferably at least about2.0%. The total concentration of alkali metal ion is calculated bydividing the sum of the mass of all alkali metal ions (i.e., not theentire salt, only in the alkali metal cations) in the depilatorycomposition by the total mass of the composition.

Compositions of the present invention may also include a cation thatforms a partially-soluble hydroxide. By “cation that forms apartially-soluble hydroxide,” it is meant a cation whose hydroxide has asolubility product at 25° C. is that less than about 10⁻², andpreferably between about 1×10⁻⁶ to about 1×10⁻². Suitable cationsinclude calcium, strontium, barium, manganese, and magnesium, withcalcium being preferred.

The cation that forms a partially-soluble hydroxide may be present in aconcentration of at least about 1%, preferably at least about 1.5%.

The compositions of the invention may further include an acceleratorsuch as urea (a highly water soluble, hydrophilic carbamide compound) toenhance the action of the keratin-degrading compound. The acceleratormay be present in the composition in a weight concentration from about3% to 10%.

The compositions of the present invention include one or morehydrophobic compounds such as oils or emollients. The hydrophobiccompounds may be, for example, any of a variety of hydrophobic materialsthat are either liquid or solid at room temperature, has a carbon orsilicon-oxygen chain length of at least about 3, more preferably atleast about 5, and is capable of spreading across the skin and forming afilm thereon, when used in a composition of the present invention.Examples of suitable water-insoluble hydrophobic compounds include, butare not limited to emollients such as oils including mineral oils,petrolatum, vegetable or animal-derived oils (triglycerides and thelike); non-hydrocarbon based oils such as dimethicone, and othersilicone oils as well as silicone gums; fragrance oils; waxes includingpolyethylene waxes, and other mixtures of fatty esters, not necessarilyesters of glycerol and the like. One example of a particularly suitablewater-insoluble, hydrophobic compound is mineral oil.

In another embodiment, the hydrophobic compound is water-soluble, suchas, for example, an emulsifier (e.g., have both hydrophobic andphydrophilic moieties on the same molecule) that may in some conditionsaugment the phase stability provided by the structured surfactant phase.Suitable emulsifiers include monomeric emulsifiers such as non-ionicemulsifiers including fatty alcohol ethoxylates, fatty esters and fattyamides; or monomeric ionic emulsifiers, polymeric emulsifiers, and thelike. One example of a particularly suitable water-soluble, hydrophobiccompound is cetearyl alcohol.

The hydrophobic compound or compounds may be present in the compositionin a total concentration of hydrophobic compounds of from about 0 toabout 20%, preferably from about 0.5% to about 15%, more preferably fromabout 2.5% to about 10%, and, most preferably in a concentration fromabout from about 2.5% to about 8.5%.

As will be recognized by those of skill in the art, the compositions ofthe present invention further comprise water, which serves to provide avehicle about which a structured phase is dispersed. The concentrationof water in the composition is sufficient to stabilize the composition,but not so great as to prevent the composition from becoming structured.In one embodiment, the concentration of water is from about 5% to about70%, preferably from about 15% to about 60%, more preferably from about20% to about 50%, and most preferably from about 25% to about 45%.

In certain embodiments of the invention, compositions of the presentinvention include other functional ingredients. By other functionalingredients it is meant any moiety that serves one or more functionseither to stabilize or provide aesthetic benefits to the composition orto impart one or more of various benefits to the end user. These variousfunctional ingredients may be of any form at room temperature (e.g.,solids, liquids, pastes and the like) and be dispersed, emulsified, orsolubilized or otherwise homogenized within the composition.

A wide variety of functional ingredients may be used in compositions ofthe present invention, although it is preferred that the ingredient doesnot adversely affect the phase stability of the composition, and it isalso preferred that the ingredient does not react prematurely with thedepilatory active. By “adversely effect the phase stability,” it ismeant that by including the particular functional ingredient, whensubject to a stability challenge (e.g., held at 22° C., 50% relativehumidity for a week; when subject to three 48 hour freeze-thaw cycles)the composition irrevocably phase separates into two or more visuallydistinct phases so as to be displeasing (e.g., in a tactile, olfactory,and/or visual sense) for topical use.

Functional ingredients that may be used include, but are in no waylimited to: dyes and colorants; ultraviolet filters and suncsreens,opacificiers, matting agents, rheology modifiers; skin conditioners;chelating and sequestering agents, pH adjusters, humectants, filmforming polymers, plasticizers, fragrance components; water solublesolvents such as glycols including glycerol, propylene glycol C₁-C₆alcohols may be incorporated into the composition (again, as long asthere is no adverse effect on stability) and various benefit agents, asdescribed below.

The functional ingredient may be water-insoluble. By “water-insoluble,”it is meant, a moiety that cannot be rendered essentially completelysoluble in deionized water at 25° C., after providing a 1% by weight ofsaid moiety in said deionized water under moderate agitation for 10minutes. A wide variety of water-insoluble components may beincorporated into compositions of the present invention. The structurednature of the composition is suitable for dispersing water insolublecomponents that are solid at room temperature (e.g., certain polymersand waxes; dyes; and particulates such as mineral oxides, silicates,aluminosilicates, zinc pyrithione, colloidal oat flour, soy derivativesand the like) or liquid at room temperature (e.g., oils, emollients, andskin conditioners; biological actives; fragrance components).

Any of a variety of commercially available secondary conditioners, suchas volatile silicones, which impart additional attributes, such as glossto the hair are suitable for use in this invention. The volatilesilicone conditioning agent has an atmospheric pressure boiling pointless than about 220° C. The volatile silicone conditioner may be presentin an amount of from about 0 percent to about 3 percent, e.g. from about0.25 percent to about 2.5 percent or from about 0.5 percent to about 1.0percent, based on the overall weight of the composition. Examples ofsuitable volatile silicones nonexclusively include polydimethylsiloxane,polydimethylcyclosiloxane, hexamethyldisiloxane, cyclomethicone fluidssuch as polydimethylcyclosiloxane available commercially from DowCorning Corporation of Midland, Mich. under the tradename, “DC-345” andmixtures thereof, and preferably include cyclomethicone fluids. Othersuitable secondary conditioners include cationic polymers, includingpolyquarterniums, cationic guar, and the like.

Any of a variety of commercially available humectants, which are capableof providing moisturization and conditioning properties to the personalcleansing composition, are suitable for use in the present invention.The humectant may be present in an amount of from about 0 percent toabout 10 percent, e.g. from about 0.5 percent to about 5 percent or fromabout 0.5 percent to about 3 percent, based on the overall weight of thecomposition. Examples of suitable humectants nonexclusively include: 1)water soluble liquid polyols selected from the group comprisingglycerine, propylene glycol, hexylene glycol, butylene glycol,dipropylene glycol, polyglycerols, and mixtures thereof; 2) polyalkyleneglycol of the formula: HO—(R″O)_(b)—H, wherein R″ is an alkylene grouphaving from about 2 to about 3 carbon atoms and b is an integer of fromabout 2 to about 10; 3) polyethylene glycol ether of methyl glucose offormula CH₃—C₆H₁₀O₅—(OCH₂CH₂)_(c)—OH, wherein c is an integer from about5 to about 25; 4) urea; and 5) mixtures thereof, with glycerine beingthe preferred humectant.

Examples of suitable chelating agents include those which are capable ofprotecting and preserving the compositions of this invention. Examplesof chelating/sequestering agents that may be suitable include EDTA,phosphates, and the like.

Suitable preservatives include, for example, parabens, quaternaryammonium species, phenoxyethanol, benzoates, DMDM hydantoin, and arepresent in the composition in an amount, based upon the total weight ofthe composition, from about 0 to about 1 percent or from about 0.05percent to about 0.5 percent.

While it is typically unnecessary to include thickening agents in thecomposition (since the “thickening” is typically aesthetically andcost-effectively accomplished using the combination of anionicsurfactant and the structuring agent, e.g., branched fatty alcohol), itis possible to incorporate any of a variety of commercially availablethickening agents, which are capable of imparting the appropriateviscosity to the personal cleansing compositions are suitable for use inthis invention.

Examples of suitable thickening agents nonexclusively include: mono ordiesters of 1) polyethylene glycol of formula: HO—(CH₂CH₂O)_(z)H,wherein z is an integer from about 3 to about 200; and 2) fatty acidscontaining from about 16 to about 22 carbon atoms; fatty acid esters ofethoxylated polyols; ethoxylated derivatives of mono and diesters offatty acids and glycerine; hydroxyalkyl cellulose; alkyl cellulose;hydroxyalkyl alkyl cellulose; hydrophobically-modified alkali swellableemulsions (HASEs); hydrophobically-modified ethoxylated urethanes(HEURs); xantham and guar gums; and mixtures thereof. Preferredthickeners include polyethylene glycol ester, and more preferablyPEG-150 distearate which is available from the Stepan Company ofNorthfield, Ill. or from Comiel, S.p.A. of Bologna, Italy under thetradename, “PEG 6000 DS”.

Compositions of the present invention may include a benefit agent. Abenefit agent is any element, an ion, a compound (e.g., a syntheticcompound or a compound isolated from a natural source) or other chemicalmoiety in solid (e.g. particulate), liquid, or gaseous state andcompound that has a cosmetic or therapeutic effect on the skin, hair,mucosa, or teeth. As used herein, the term “benefit agent” includes anyactive ingredient such as a cosmetic or pharmaceutical, that is to bedelivered into and/or onto the skin, hair, mucosa, or teeth at a desiredlocation.

The benefit agents useful herein may be categorized by their therapeuticbenefit or their postulated mode of action. However, it is to beunderstood that the benefit agents useful herein may, in somecircumstances, provide more than one therapeutic benefit or operate viagreater than one mode of action. Therefore, the particularclassifications provided herein are made for the sake of convenience andare not intended to limit the benefit agents to the particularapplication(s) listed.

Examples of suitable benefit agents include those that provide benefitssuch as, but not limited to: emollients, moisturizing and water-lossprevention agents; cleansing agents; depigmentation agents; reflectantsand optical modifiers; amino acids and their derivatives; antimicrobialagents; allergy inhibitors; anti-acne agents; anti-aging agents;anti-wrinkling agents, antiseptics; analgesics; shine-control agents;antipruritics; local anesthetics; anti-hair loss agents; hair growthpromoting agents; hair growth inhibitor agents, antihistamines;antiinfectives; anti-inflammatory agents; anticholinergics;vasoconstrictors; vasodilators; wound healing promoters; peptides,polypeptides and proteins; deodorants and anti-perspirants; medicamentagents; skin firming agents, vitamins; skin lightening agents; skindarkening agents; antifungals; depilating agents; counterirritants;hemorrhoidals; insecticides; enzymes for exfoliation or other functionalbenefits; enzyme inhibitors; poison ivy products; poison oak products;burn products; anti-diaper rash agents; prickly heat agents; vitamins;herbal extracts; vitamin A and its derivatives; flavenoids; sensates andstress-reducing agents; anti-oxidants; hair lighteners; sunscreens;anti-edema agents, neo-collagen enhancers, anti-dandruff/sebhorreicdermatitis/psoriasis agents; keratolytics; lubricants; lightening andwhitening agents; calcification, fluoridation and mineralization agents;and mixtures thereof.

The amount of the benefit agent that may be used may vary dependingupon, for example, the ability of the benefit agent to penetrate throughthe skin, nail, mucosa, or teeth; the specific benefit agent chosen, theparticular benefit desired, the sensitivity of the user to the benefitagent, the health condition, age, and skin and/or nail condition of theuser, and the like. In sum, the benefit agent is used in a “safe andeffective amount,” which is an amount that is high enough to deliver adesired skin or nail benefit or to modify a certain condition to betreated, but is low enough to avoid serious side effects, at areasonable risk to benefit ratio within the scope of sound medicaljudgment.

Compositions of the present invention are structured, i.e., have a YieldStress from about 1 Pascal (Pa) to about 1500 Pa; more preferably fromabout 10 Pa to about 1100 Pa and preferably include a lamellar phasethat is largely composed of one or more surfactants that is dispersedwithin an exterior (typically aqueous) phase. The viscosity of thepersonal care composition may be such that the composition is spreadablesuch as that of a cream or lotion or gel. For example. when measuredusing a LVT3 spindle at 30 rpm, the viscosity may be from about 500 cpsto about 2000 cps.

In certain embodiments of the invention the viscosity of the compositionis particularly stable over time. For example, the percent change inviscosity from an initial reading to the viscosity of a composition agedfor 2 weeks at 25° C. may be less than about +/−15%, preferably lessthan about +/−10%. Similarly the change in viscosity from one taken at 2weeks aging at 25° C. to one taken at 13 weeks aging at 25° C. may beless than +/−25%, preferably less than about +/−10%. Similarly thechange in viscosity from an initial reading to the viscosity of acomposition having undergone 3 freeze-thaw cycles may be less than+/−15%, preferably less than about +/−10%.

The pH of the present compositions is not critical, but may be in arange that provides sufficient depilation, yet does not facilitateirritation to the skin, such as from about 7.5 to about 13, preferablyfrom about 11 to about 13, and more preferably from about 12 to about12.5. In certain embodiments, the pH of the composition is particularlystable over time. For example the change in pH from an initial readingto one taken at 2 weeks aging at 25° C. may be less than about +/−0.05units. Similarly the change in pH from one taken at 2 weeks aging at 25°C. to one taken at 13 weeks aging at 25° C. may be less than +/−0.075units. Similarly the change in pH from an initial reading to thecomposition having undergone 3 freeze-thaw cycles may be less than+/−0.05.

In one embodiment of the present invention the structured compositioncomprises at least two visually distinct phases wherein a first phase isvisually distinct from a second phase. Preferably, the visually distinctphases are packaged in physical contact with one another and are stable.Preferably, the visually distinct phases form a pattern such as stripes,ribbons, or striations. The ratio of a first phase to a second phase istypically from about 1:99 to about 99:1, preferably from 90:10 to about10:90, more preferably about from 70:30 to about 30:70, still even morepreferably about 50:50. As known in the art, the first visually distinctphase may include the components in a manner sufficient to providestructure, e.g., anionic surfactant and branched fatty alcohol. Thesecond visually distinct phase may also include the above-mentionedcomponents in a manner sufficient to provide structure. Alternatively,the second phase may be unstructured.

Compositions of the present invention are typically extrudable ordispensable from a package, such as to be applied directly orindirectly, topically or orally to the body or another surface.Depending upon the particular function, compositions of presentinvention may be rinsed with water or rubbed onto the skin and allowedto remain without rinsing. Preferably, the compositions of the presentinvention are rinse-off formulations, by which is meant the product isapplied topically to the skin or hair and then subsequently (i.e.,within minutes) the skin or hair is rinsed with water, or otherwisewiped off using a substrate or other suitable removal means withdeposition of a portion of the composition. Particularly suitable usesfor compositions of the present invention include body washes andconditioners as well as hair shampoos and conditioners, and facialcleansers. Compositions of the present invention may also be used forcleansers with acne-treatment benefit agents, stress-relief compositions(e.g. compositions with high concentrations of fragrant compounds),among other personal care applications.

In certain embodiments, the compositions produced via the presentinvention are preferably used as or in personal care products forremoving hair from a body surface. By “body surface” it is meant thatportion of the body encompassing a surface of the body from whichunwanted hairs protrude (i.e., skin) and/or the hairs protrudingtherefrom. Examples of body surfaces include the bikini area, legs, armsand/or areas of the face such as around the eyebrows or lips.Compositions of the instant invention due to the presence of surfactantfurther provide enhanced ability to cleanse the skin in addition toremoving hair.

As discussed above, applicants have discovered unexpectedly that theinstant methods provide personal care products having good aesthetics,and in certain embodiments have one or more of desirable properties suchas stability, rinsability and hair removal efficacy.

The present invention provides methods of removing hair and/or cleansinga body surface of the human body comprising contacting at least aportion of the body with a composition of the present invention. Certainpreferred methods comprising contacting a body surface with acomposition of the present invention to remove hair from and cleanse thebody surface.

The hair removal methods of the present invention may further compriseany of a variety of additional, optional steps associated conventionallywith removing hair including, for example, lathering, rinsing steps, andthe like.

The present invention further provides methods of making a structuredcomposition comprising an depilatory active comprising combining andepilatory and a surfactant, such as in a manner sufficient to achieve acomposition having a Yield Stress of from about 1 Pa to about 1500 Pa.For example, one or more structured compositions comprising, consistingessentially of, or consisting of depilatory active, a branched fattyalcohol, and anionic surfactant may be combined by pouring, mixing,adding dropwise, pipetting, pumping, and the like, any one or more ofsuch ingredients or compositions comprising such ingredients into anyone or more of the other ingredients or compositions comprising suchother ingredients in any order and optionally using any conventionalequipment such as a mechanically stirred propeller, paddle, and thelike.

The methods of the present invention may further comprise any of avariety of steps for mixing or introducing one or more of the optionalcomponents described hereinabove with or into the structured compositionof the present invention either before, after, or simultaneously withthe combining step described above. While in certain embodiments, theorder of mixing is not critical, it is preferable, in other embodiments,to pre-blend certain components, such as the fragrance and the nonionicsurfactant before adding such components into the structuredcomposition.

EXAMPLES

The following Yield Stress Test is used in the instant methods and inthe following Examples. In particular, as described above, the YieldStress test is used to determine whether a composition is structured,according to the present invention. Furthermore, the Degree of HeapingTest is used to determine the ability of the composition to recovershape rapidly.

Yield Stress Test:

The following Yield Stress Test was performed on various personal carecompositions to determine the Yield Stress according to the presentinvention. Samples were placed in a water bath set at 25° C. for aperiod time sufficient to allow the sample to equilibrate (at leastabout an hour). The procedure was accomplished by gently placing about1.0 grams of the composition to be tested was on the base plate of aproperly calibrated rheometer (e.g., Advanced Rheometer AR 2000) havinga 20 mm cone with a 1 degree angle, a 20 mm plate, a water bath, and asolvent trap. The sample size was just sufficient to allow some minorflow of the sample out of the gap once the final position of the coneand plate was reached (0.030 mm). To minimize shearing of the sampleprior to testing, each sample was applied to the plate in a consistentmanner, by gently scooping out the sample in one motion withoutsignificant shear or spreading, evenly layered on the plate, and withoutcompressing and rotating the spatula away from the sample. The samplewas centered on the base plate and laid relatively even across theplate. Once the measurement position was reached, a small bulge of thesample material protruded from the gap. This was removed quickly andgently so as not to disturb the top plate and pre-shear the sample. [Ifthe top plate was moved then the run was aborted.] The samplepreparation described thus far was less than 20 seconds to reduce unduedrying of the sample. The instrument was set for a controlled shear raterun (log) with a shear rate spanning from 0.01^(·−1), to 300^(·−1); 300data points collected; 300 seconds test duration; 25° C. water bath. Theoutput device attached to the rheometer was set to plot stress (Pa) as afunction of shear rate s⁻¹. Yield stress was determined from the plot ofyield stress versus shear rate as the stress at which the curve departsfrom linearity. The average and standard deviation of the 3 runs wasdetermined.

Degree of Heaping Test:

The following Degree of Heaping Test was performed on various personalcare compositions to determine the H-B Dimension according to thepresent invention.

Immediately after completing the Yield Stress Test above, the cone wasthen removed from the plate using the automated lift motor on therheometer. The sample was left on the plate for 30 minutes and a digitalpicture was taken with a Canon S25, 5 megapixel camera. The picture isevaluated using a box counting technique method, starting with a boxscale of one box covering the plate sample area and doubling the numberof boxes with each iteration until the number of boxes equals onethousand and twenty four. The H-B dimension of the material iscalculated by plotting log N(1) versus log 1, where N(1) is a number ofboxes containing any surface of the material and 1 is a resolutionrepresenting the reciprocal of the number of the boxes (i.e., boxresolution) and wherein the H-B dimension is a straight line slope ofthe plot from eight boxes to one thousand and twenty four boxes. Thetest method repeated so that 10 replicates were performed for eachsample. If the resulting H-B dimension has a relative standard deviationof less than 10% the value is reported for the sample.

Examples Ex. 1-Ex. 2 Preparation of Inventive Examples and Evaluation ofStability and Depilation

The inventive structured compositions of Comparative Example Ex. 1 andExample Ex. 2 were prepared by blending a particular ingredient withother ingredients according to the materials and amounts listed in Table1:

TABLE 1 Concentration (wt %) Trade Name INCI Name Ex. 1 Ex. 2 DeionizedWater Water 1.898  7.500 Tegobetaine L-7V (32%) Cocamidopropyl Betaine(and) Water 26.000 — Mackol CAS 100-N Sodium Coco Sulfate 1.500 — Emery917 Glycerin 3.000 — Jaguar C17 Guar Hydroxypropyltrimonium Chloride0.500 — Cedapal TD403 (30%) Sodium Trideceth Sulfate 18.000 31.000Isalchem 123A Alcohols, C10-16 2.000  2.000 D&C Red 28 Aluminum Lake D&CRed 28 Aluminum Lake 0.002 — Procol CS 20 D Cetearyl Alcohol (and)Ceteareth-20 7.500 — Deionized Water Water 6.000 — Urea Urea 8.000 8.000 Deionized Water Water 5.000  5.000 Calcium Hydroxide CalciumHydroxide 4.000  4.000 Potassium Thioglycolate (43%) PotassiumThioglycolate 16.000 16.000 Water Lily Fragrance Fragrance 0.600 —Bioterge AS-40 Socium C14-16 Olefin Sulfonate — 25.000 Deionized WaterWater qs — Sodium Hydroxide Sodium Hydroxide qs  1.500 pH (initial)12.850 12.974 pH (1 week @ 25° C.) 12.750 12.974 (3 days) pH (1 week @50° C.) 12.600 12.971 (3 days) viscosity (initial) 250,000 viscosity (1week @ 25° C.) 340,000 viscosity (1 week @ 50° C.) 1,260,000

The structured compositions noted in Table 1 were prepared as follows:Ingredients were added in the order listed to a suitable size vesselequipped with an overhead propeller type mixer. Agitation was sufficientto maintain good batch movement without aeration. Components were addedwhile maintaining constant agitation. pH was measured after the lastcomponent was added and adjusted to 5.5-6.5 Citric acid was then addedto reduce to pH to between about 5.7. Specifically 0.12%, 0.11%, and0.10% of citric acid was added to Ex. 1, Ex. 2 respectively to reducethe pH to 5.70, 5.70 and 5.74 respectively. Examples Ex. 1-Ex. 2 wereevaluated for viscosity using a standard Brookfield DV-I+ viscometerwith rotating LVT3 spindle at 30 rpm, with values in centipoise (cps)reported in Table 1.

Ex. 1 and Ex. 2 were applied to a body surface and allowed to remain forseveral minutes. The depilatory composition was then removed. Thecompositions were successful at removing hair. Viscosity stability forEx. 1 evaluated after 1 week at 50° C. was not as good as expected, butthese conditions are considered a very demanding challenge for adepilatiory composition. Ex. 2 also showed excellent creamy aestheticsand excellent stability after a limited 3 day evaluation.

Examples Ex. 3-Ex. 4 Preparation of Inventive Examples and Evaluation ofStability and Depilation

The inventive structured compositions of Examples Ex. 1 and Ex. 2 wereprepared by blending a particular ingredient with other ingredientsaccording to the materials and amounts listed in Table 2:

TABLE 2 Trade Name INCI Name Ex.3 Ex.4 Deionized Water Water 3.00024.000 Cedapal TD403 (30%) Sodium Trideceth 34.600 24.000 SulfateIsalchem 123A Alcohols, C10-16 2.200 1.500 Urea Urea 8.000 8.000 CalciumHydroxide Calcium 4.000 4.000 Hydroxide Potassium Potassium 16.00016.000 Thioglycolate (43%) Thioglycolate Bioterge AS-40 Socium C14-1630.700 21.000 Olefin Sulfonate Sodium Hydroxide Sodium 1.500 1.500Hydroxide pH (initial) 12.780 12.77 pH (2 week @ 25° C.) 12.790 12.75 pH(2 week @ 50° C.) 12.740 12.68 pH (13 week @ 25° C.) 12.820 12.81 pH (13week @ 50° C.) 12.740 12.64 pH (freeze thaw - 3 cycles) 12.740 12.72viscosity (initial) (cps) 25,800 12250 viscosity (2 week @ 25° C.)22,310 12250 viscosity (2 week @ 50° C.) 26,600 14350 viscosity (13 week@ 25° C.) 27,030 11350 viscosity (13 week @ 50° C.) 27,620 15720viscosity (freeze thaw - 25,060 12,100 3 cycles)

The inventive structured compositions noted in Table 2 were prepared ina manner similar to those described above with reference to Table 1. Ex.3 and Ex. 4 were applied to a body surface and allowed to remain forseveral minutes. The depilatory composition was then removed. Theinventive compositions were successful at removing hair. Ex. 3 and Ex. 4showed excellent creamy aesthetics. By using the alkyl olefin sulfonateto aid in structuring the composition, it is also possible to achieveexcellent pH stability, excellent freeze thaw stability and excellentviscosity stability. Unlike Ex. 1, the changes in pH (between initialand either 2 weeks at 25° C. or freeze thaw; or between 2 weeks at 25°C. and 13 weeks at 25° C.) are all less than 0.05 units. Furthermore,unlike Ex. 1, the changes in viscosity (between initial and either 2weeks at 25° C. or freeze thaw; or between 2 weeks at 25° C. and 13weeks at 25° C.) are all less than +/−15%.

What is claimed is:
 1. A composition comprising: a depilatory activeselected from the group consisting of thioglycolates; from 21% to about30% of an alkyl olefin sulfonate anionic surfactant; optionally, asecond anionic surfactant which may be branched or unbranched and isselected from the group consisting of alkyl sulfates, alkyl ethersulfates, alkyl monoglyceryl ether sulfates, alkyl sulfonates, alkylarylsulfonates, alkyl sulfosuccinates, alkyl ether sulfosuccinates, alkylsulfosuccinamates, alkyl amidosulfosuccinates, alkyl carboxylates, alkylamidoethercarboxylates, alkyl succinates, fatty acyl sarcosinates, fattyacyl amino acids, fatty acyl taurates, fatty alkyl sulfoacetates, alkylphosphates, and mixtures thereof; and from about 0.5% to about 5% of astructuring aid selected from the group consisting of C₁₁-C₁₅ linear orbranched fatty acids or fatty alcohols, wherein the composition has anH-B dimension of less than about 1.7 and a pH of from about 11 to about13 and further wherein the composition is substantially free ofsurfactants comprising one or more amide functional groups.
 2. Thecomposition of claim 1, wherein the composition further comprises amonobranched fatty alcohol.